Simultaneous placement and assignment for exploration in mobile backbone networks

This paper presents new algorithms for conducting cooperative sensing using a mobile backbone network. This hierarchical sensing approach combines backbone nodes, which have superior mobility and communication capability, with regular nodes, which are constrained in mobility and communication capability but which can sense the environment. In the framework of a cooperative exploration problem, a technique is developed for simultaneous placement and assignment of regular and mobile backbone nodes. This method, a generalization of existing techniques that only consider stationary regular nodes, optimally solves the simultaneous placement and assignment problem in computationally tractable time for problems of moderate size. For large-scale instances of this problem, a polynomial-time approximation algorithm is developed. This algorithm carries the benefit of a theoretical performance guarantee and also performs well in practice. Finally, the simultaneous placement and assignment technique is incorporated into a cooperative exploration algorithm, and its performance is shown to compare favorably with that of a benchmark based on existing assignment algorithms for mobile backbone networks.